Mitosis - Cytokinesis

Description:

Cytokinesis is the division of protoplasm into two daughter cells. It takes place after the nuclear division or karyokinesis has been performed by cell. Cell organelles are distributed equally between the two cells during the process of cytokinesis. At times cytokinesis do not follow karyokinesis and it results in the production of a multinucleate condition called coenocyte or syncytium.

Normally cytokinesis starts towards the middle anaphase and is completed simultaneously with telophase.

Animal Cytokinesis

The changes an animal cell undergoes during cytokinesis are −

• The central equatorial part of spindle gets changed into dense fibrous structure called midbody.

• Microfilaments collect in the middle region of the cell below the cell membrane.

• Microfilaments induce the cell membrane to invaginate.

• The furrow deepens centripetally and cleaves the cell into two daughter cells. This method is called cleavage cytokinesis.



Plant Cytokinesis

Plant cytokinesis is different form the animal cytokinesis due to the presence of cell wall. Plant cytokinesis can happen in two methods −

• Cleavage method

  • Cytoplasm undergoes centripetal constriction in the middle to form two daughter protoplast.
  • Pectin hemicellulose and microfibrils of cellulose are deposited to form a double wall.

• Cell Plate method

  • Common method in plant cells.
  • In this case the spindle persist for sometime which is known as phragmoplast.
  • A matrix or a film is formed by the membrane of the vesicles.
  • The film becomes solidified to form the cell plate.